I have a 2013 x-10 also since it is as you said the "all round boat" and was looking into a boom. This one just does not look right, from the photos the bar is above the windshield which is great for some upward pull but I think it would be impossible to have a small child hang from it and have their feet even touch the water.

Let us know what you find out on this. Just based off of my boat having it mount somwhere around the base of the tower would still give plenty of height, but I know mounting spots are hard to find.